A Research On Glucose Biosensor Based On Cobalt Phosphide,N,S-Carbon And Cnts Modified Enzyme Electrode

Modern pathology and medical research have shown that for diabetic patients,the risk of kidney,retina and neurological complications is directly related to the increase in chronic blood glucose.Therefore,the development of fast and reliable blood glucose concentration or blood glucose level detection method is of great significance.Clark and Lyons reported the first enzyme electrochemical glucose biosensor in 1962.Although such sensors have shown high sensitivity and high selectivity,there are still many problems,including the introduction of enzymes to increase costs,the process of immobilizing enzymes,and the loss of enzyme activity.Therefore,how to develop carrier materials with high conductivity,high biocompatibility and high load of enzymes is of great significance in the development of enzyme electrochemical glucose biosensors.In this paper,based on the literature theory reported in the past,combined with a period of experiment,three kinds of nano-carrier materials which can be used for immobilization of GOx enzyme were prepared,and the prepared GOx/nanomaterial composite electrode was tested as glucose sensor in electrochemical workstation system.1、CoP nanowire array（CoP NA/TM）was prepared by hydrothermal method on TM,GOx was fixed on the surface of CoP NA/TM electrode using Nafion to obtain GOx/CoP NA/TM electrode,and electricity of two electrodes was passed through electrochemical workstation.Chemical properties were tested.The obtained samples were characterized by XRD,SEM,TEM,XPS and other test methods.The performance of the CoP NA/TM and Nafion/GOx/CoP NA/TM electrodes for electrocatalytic oxidation of glucose was tested using cyclic voltammetry and i-t method.The experimental results show that the glucose sensor constructed by CoP NA/TM electrode has high catalytic performance with a linear detection range of 0.0005–1.5 mm,a sensitivity of 5168.6 mA mM^-1 cm^-2,and a minimum detection limit of 0.1μM（S/N=3）,stability and reproducibility meet the requirements.It has the advantage of significantly catalyzing the oxidation of glucose compared to other reported Co-based nanomaterials.On this basis,the Nafion/GOx/CoP NA/TM electrode obtained by immobilizing GOx was used as the electrolyte with PBS solution.Due to the limitation of the enzyme,the cyclic voltammetry test has a weak response when catalyzing the oxidation of glucose,and the linear detection range is 0.1⁷ mM,the minimum detection limit is 0.6μM（S/N=3）,and the Michaelis constant Km=0.28 mmol/L,but also due to the specificity of the enzyme,it is extremely high when the chronoamperometry is used to test the interference.2、Herein,N,S-C mixed powder was prepared by one-step synthesis method,and GOx and N,S-C powder were modified on the surface of GC electrode using chitosan to obtain CS/GOx/N,S-C/GC electrode.The obtained sample was scanned by electron microscope,Fourier.Characterization by test methods such as infrared spectroscopy.CS/GOx/N,S-C/GC electrode electrochemical catalyzed glucose oxidation potential in a three-electrode system with Ag/AgCl as the reference electrode,platinum wire as the counter electrode,CS/GOx/N,S-C/GC electrode The working electrode,0.1 M PBS（pH=7.4）solution is the electrolyte,and the CV method and the it method are still the main methods for testing the electrochemical performance.The experimental results show that the CS/GOx/N,S-C/GC electrodes have excellent catalytic properties for glucose oxidation.The built-in glucose sensor has a linear detection range of 0.1 to 10 mM and a minimum detection limit of 1.4μM（S/N=3）,the Michaelis constant Km=0.41 mmol/L,and the selectivity exhibited during the interference test is very good.3、The aniline was polymerized on the surface of the multi-walled carbon nanotube by hydrothermal synthesis to obtain PANI/CNTs powder.The Nafion/GOx/PANI/CNTs/GC electrode was obtained by modifying GOx and PANI/CNTs on the surface of the GC electrode using Nafion and exploring the performance of the enzyme electrode for catalyzing glucose oxidation.The prepared samples were characterized by scanning electron microscopy.The potential of electrochemical catalyzed glucose oxidation by Nafion/GOx/PANI/CNTs/GC electrodes was carried out in a three-electrode system with Ag/AgCl as the reference electrode and platinum wire as the counter electrode.The Nafion/GOx/PANI/CNTs/GC electrode was The working electrode,0.1 M PBS（pH=7.4）solution is the electrolyte,and the CV method and the it method are still the main methods for testing the electrochemical performance.The experimental results show that Nafion/GOx/PANI/CNTs/GC can exhibit high catalytic oxidation performance for glucose in neutral PBS electrolyte,and linear detection range of Nafion/GOx/PANI/CNTs/GC electrode as glucose sensor.For the range of 0.1 to 5 mM,the minimum detection limit is 0.9μM（S/N=3）,and the Michaelis constant Km=0.31 mmol/L.The stability and reproducibility are within the target requirements,and the selectivity is very good.The electrode has a comprehensive ability as an enzyme glucose sensor.